Doctrine of Equivalents was set forth by US Supreme Court in 1950 to extent the protection of patent rights to a good patent holders beyond the literal meaning of the claims i.e. literal infringement. US Supreme Court also established Function-Way-Result test with the objective to ensure the fundamental fairness to it to all.

Reverse of the doctrine is also hold good, i.e. if the claim elements did not Function is the same Way to accomplish the same Result then there would not be actual infringement under the doctrine.

Till date, neither US Supreme Court nor Federal Circuit Courts of Appeal had reversed a finding of non-infringement based on reverse doctrine of equivalence.